I wanted to make note of a few surprises that have come to mind in reading. Information is just not clear at all at times. With regard do the class and sub classes they did a poor job explaining. Many times you read rules that address a class, but seem to not include the sub classes. Later in reading on you have similar text that logically must be applied to subclasses, like the int table for magic users and illusionists, Later this class / sub class is directly explained. Why wasn't this done in the beginning and if you get the Unearthed Arcana, forget what I just said.
Gygax was working on the Mini Haul school of game mastery from the start. Look at his advice to have people bring first level characters into an existing campaign. Even more telling are his statements on being stingy followed by his 100gp a level, monthly gold tax. What the hell dude we are still trying to pay for our in and you want to tax my party 100gp a head at first level? We are averaging an encounter a day in our first level AD&D game, we are going to be broke forever! We are just trying to get to the point where we have all the equipment we need to be start, let alone plate armor.
My final observation was something I have been looking for, specifically. This would be rules for head shots. In a campaign with my cousins we had this rule of intelligent creatures making 1 in 2 attacks to the head, with non intelligent doing 1 in 6. The effect was double damage for the head shot. This was something I never have been able to find, until today, and always wondered about its source. It seems to come out of the Helmet rules in the DMG, which state this about players not wearing a helmet. Basically they are saying if you have no helmet you are ac 10 but with the helmet ac 1. I have no idea about double damage for head shots though. I wonder if it was read somewhere else then strapped on to form a sort of critical attack rule?